Auto-opening umbrella frame

ABSTRACT

An enhanced frame of an auto-opening umbrella comprises hollow cylindrical intermediate pivotal joints with spreaders passed through and each including two spaced bottom lugs, a shaft integrally formed with the lugs, and a recess between the lugs. A plurality of links has hooked ends pivotably coupled to a lower ring and the shaft. The outer hooked end of each link is sufficiently smaller than the recess so that ribs are spaced apart from the spreaders by a much smaller distance when the umbrella is folded. This can achieve a smooth folding operation and a more compact umbrella after folded.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to umbrellas frame and more particularly to an auto-opening umbrella in which the spreaders and its pivotal joint are made more durable and the umbrella can be used smoothly and stored more compactly.

[0003] 2. Description of Related Art

[0004] It is common for people to carry an umbrella while going out. This is particularly true in countries having abundant rain year round. In particular, a convenient auto-opening umbrella is desirable for many people due to its quick opening operation. However, auto-opening umbrella tends to malfunction. This is mainly because spring provided therein as detailed by referring to FIG. 5. As shown, frame of the umbrella supported by a center post 100 comprises a lower ring 101, an upper ring 103, a hub 104, a spring 102 biased between lower ring 101 and upper ring 103, a plurality of ribs 105 extended from hub 104, a plurality of first connection members 107 on ribs 105, a plurality of spreaders 106 coupled between upper ring 103 and first connection members 107, and links 108 coupled between spreaders 106 and lower ring 101. As understood that, the opening of auto-opening umbrella is effected by suddenly expanding the spring 102. Hence, the expansion force is large. Unfortunately, pin 109 for coupling link 108 to spreader 106 is relatively small. It is also understood that spreaders 106 are formed of U-shaped thin metal material by punching for reducing weight. In view of above, it is understood that the securing of pins 109 on spreaders 106 and links 108 may neutralize (because pins 109 are deformed, detached or rusted) after a predetermined long period of time (or even a short time) of use due to the large expansion force of spring 102.

[0005] Thus, it is desirable to provide an improved auto-opening umbrella in order to overcome the above drawbacks of prior art.

SUMMARY OF THE INVENTION

[0006] It is an object of the present invention to provide an auto-opening umbrella having enhanced frame wherein a shaft of pivot joint between link and spreader is formed integrally with connection member put on spreader so as to possess sufficient support strength, thereby prolonging a useful life.

[0007] It is another object of the present invention to provide an auto-opening umbrella having enhanced frame wherein a shaft of pivot joint between stainless steel link and fiber re-enforced plastic (FRP) spreader is formed integrally with plastic connection member. This has the advantages of minimum noise generated at the joint during operation, providing a rustproof pivot joint, no riveting in assembly, convenient, fast, and lower cost.

[0008] The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is an exploded perspective view of a preferred embodiment of a portion of frame of auto-opening umbrella according to the invention;

[0010]FIG. 2 is a side view of a portion of the umbrella frame of FIG. 1 which is in an open state;

[0011]FIG. 3 is an enlarged fragmentary view of FIG. 2 for detailing a pivotal relationship between a link and the intermediate pivotal joint which is sleeved on a spreader;

[0012]FIG. 4 is side view of the umbrella in a folded state; and

[0013]FIG. 5 is an exploded perspective view of a conventional auto-opening umbrella.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Referring to FIGS. 1 to 4, there is shown an auto-opening umbrella frame constructed in accordance with the invention. The frame comprises a shank 10, a plurality of links 19 formed of stainless steel, a plurality of single-rod ribs 15, and a plurality of twin-rod spreaders 17 both formed of FRP bar for keeping from rust. Also, the number of links 19, ribs 15, and spreaders 17 are equal. Shank 10 comprises a lower ring 11 slidable on the shank, a intermediate ring 13 also slidable on the shank, a stationary upper hub (not shown) fixed on the top of the shank, and a spring (e.g., coil spring) 12 biased between the intermediate and the lower rings 11 and 13. An equal number of latches 16 are sleeved on the ribs 15 and pivotably coupled to the spreaders 17. Note that such connection is well known. Thus a detailed description thereof is omitted herein for the sake of brevity.

[0015] For obtaining a lightweight frame and preventing pivot joint between link 19 and spreader 17 from rusting, frame is formed of FRP rods by plastic extrusion molding. Ribs 15 have a larger diameter single rod while spreader 17 consist of two connected parallel rods of smaller diameter. Also, latch 16 and intermediate pivotal joint 18 are formed of strong nylon by plastic injection molding. Link 19 is shaped to have two hooked ends 191 and 192 wherein the inner hooked end 191 is pivotably coupled to the lower ring 11 in a well known manner. Thus a detailed description thereof is omitted herein. Spreader 17 comprises an outer joint 172 having pivotal hole 171 pivotably coupled to the rib 15 and an inner joint 173 having hole 175 pivotably coupled to the intermediate ring 13, two apertures 174 formed on the twin hollow tube of joint 173 for permitting an adhesive or any of other bonding materials to fill into for securing the joint 173 to the twin bar spreader 17. Such connection is also well known. Thus a detailed description thereof is omitted herein. The characteristics of the invention are further detailed below. A substantially hollow cylindrical intermediate pivotal joint 18 comprises two connected parallel tubes 180 having central through hole 181-181 in communication with each other wherein two parallel rods 170-170 of spreader 17 are inserted through, a plurality of apertures 184 formed on the twin hollow tube for permitting an adhesive or any of other bonding materials to fill into for securing the intermediate pivotal joint 18 to the twin bar spreader 17, two spaced bottom lugs 185-185 extending vertically from the bottom of the intermediate pivotal joint 18, a shaft 186 which is across the lugs 185-185, and is integrally formed with the lugs 185-185, the diameter of shaft 186 being large enough to sustain the expansion force of spring 12 transmitted via link 19 which has its upper hook end 192 pivotably secured around the shaft 186 so as to possess a sufficient support strength, thereby prolonging a useful life of the umbrella, and a recess 187 between the lugs 185-185 and above the shaft 186, the recess 187 having a length longer than that of the bottom portion of the lug 182.

[0016] Moreover, the outer hooked end 192 of link 19 is disposed around more than half of the circumference of the shaft 186 (see FIG. 4). This has an advantage of effecting a smooth operation of the link 19 relative to the intermediate pivotal joint 18 when the spring 12 is expanded for opening the umbrella. The smooth operation is made possible because an allowance of the outer hooked end 192 in the recess 187 is relatively large, i.e., the outer hooked end 192 is sufficiently smaller than the recess 187. The invention further includes a benefit of being more compact in a storage state. This is best illustrated in FIGS. 4. Also, the projected distance of each lug 185 is made as small as possible. Further, as stated above, the ribs 15 are spaced apart from the spreaders 17 by a distance much smaller than that of prior art in an storage state of the umbrella. As such, the umbrella is advantageous in consideration of storage, packing, and transportation.

[0017] The benefits of this invention include: Minimum noise generated from the engagement of shaft 186 and upper hooked end 192 during opening or closing operation of umbrella; the joint of shaft 186 and upper hooked end 192 is rustproof; and smooth opening or closing operation of umbrella. Most importantly, such umbrella is reliable and durable.

[0018] While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims. 

What is claimed is:
 1. A frame of an auto-opening umbrella comprising: a shank including a lower ring slidable on the shank, a intermediate ring slidable on the shank, a stationary upper hub fixed on a top of the shank, and elastic means biased between the intermediate and the lower rings; a rib assembly including a plurality of ribs; a spreader assembly including a plurality of spreaders being pivotably coupled to both the ribs and the intermediate ring; and a plurality of links each having an inner hooked end and an outer hooked end wherein the inner hooked ends are pivotably coupled to the lower ring; wherein a plurality of substantially hollow cylindrical intermediate pivotal joints each comprises two connected parallel tubes having central through hole in communication with each other wherein each of the spreaders is inserted therethrough and fastened therein, two spaced bottom lugs vertically extending from the bottom of the intermediate pivotal joints, a shaft integrally formed with the lugs and across the lugs, and the outer hooked end of each link is pivotably coupled to the shaft.
 2. The frame of claim 1, wherein each of the intermediate pivotal joints has a recess between the lugs and above the shaft, and the recess having a length longer than that of a bottom portion of the lugs.
 3. The frame of claim 1, wherein the link is made of stainless steel.
 4. The frame of claim 1, wherein the outer hooked end of each link is disposed around more than half of a circumference of the shaft.
 5. The frame of claim 4, wherein the outer hooked end of each link is smaller than the recess so that the ribs are spaced apart from the spreaders by a substantially little distance when the umbrella is folded.
 6. The frame of claim 1, wherein the rib assembly has a plurality of single-rod ribs.
 7. The frame of claim 1, wherein the spreader assembly has a plurality of two parallel rod spreaders. 